Method of processing target substrate

ABSTRACT

A method of processing a target substrate includes a process of serially executing multiple processes including a main process and first to M-th subprocesses (where M is a positive integer). An index value indicating one execution of the main process is accumulated for each execution of the main process. The main process is executed multiple times in the process of serially executing multiple processes. An i-th subprocess (where i is a positive integer that satisfies 1≤i≤M) is executed once or multiple times in the process of serially executing multiple processes, and is executed subsequent to one or multiple consecutive executions of the main process. The i-th application and execution conditions are changeable.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims the benefit of priority fromJapanese Patent Application No. 2017-197024, filed on Oct. 10, 2017, theentire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a method of processing a targetsubstrate.

BACKGROUND

In a manufacturing process of a semiconductor device, various processessuch as etching, film formation, and the like are sequentially executedon a wafer. Before and after the manufacturing process, the interior ofa process chamber is cleaned. After the execution of each process, a gasused for the execution of the process is purged.

A technique for shortening the gas cleaning preparation time andimproving the throughput by changing from a gas cleaning process that isperformed for every single lot to a gas cleaning process that isperformed for every two or more lots has been disclosed. Further, atechnique of performing the cleaning for each type of process byperforming the cleaning according to the type of process has beendisclosed. In addition, a technique intended to perform the cleaningunder an appropriate cleaning condition and at an appropriate timingwhen switching lots has been disclosed.

When multiple processes are serially executed in the manufacturingprocess of a semiconductor device, an execution aspect of each processsuch as the order of executing the process, the timing of executing theprocess, or the like may affect the manufacturing efficiency or the likeof the semiconductor device. Therefore, when multiple processes areserially executed, there is a desire for a technique capable of flexiblysetting an execution aspect of each process such as the order ofexecuting the process, the timing of executing the process, or the like.

SUMMARY

Some embodiments of the present disclosure provide a method ofprocessing a target substrate. The method includes a process of seriallyexecuting multiple processes including a main process and first to M-thsubprocesses (where M is a positive integer), wherein an index valueindicating one execution of the main process is accumulated for eachexecution of the main process, the main process is executed multipletimes in the process of serially executing multiple processes, an i-thsubprocess (where i is a positive integer that satisfies 1≤i≤M) isexecuted once or multiple times in the process of serially executingmultiple processes, the i-th subprocess is executed subsequent to one ormultiple consecutive executions of the main process, the i-th subprocessis applied to the process of serially executing multiple processes whena cumulative value of the index value accumulated from a start of theprocess of serially executing multiple processes satisfies an i-thapplication condition, when the cumulative value of the index valueaccumulated from the start of the process of serially executing multipleprocesses satisfies the i-th application condition, the i-th subprocessis executed at a time when a cumulative value of the index valueaccumulated from execution of a last executed subprocess when there is asubprocess already executed from the start of the process of seriallyexecuting multiple processes or a cumulative value of the index valueaccumulated from the start of the process of serially executing multipleprocesses when there is no subprocess already executed from the start ofthe process of serially executing multiple processes satisfies an i-thexecution condition, and both the i-th application condition and thei-th execution condition are changeable.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the presentdisclosure, and together with the general description given above andthe detailed description of the embodiments given below, serve toexplain the principles of the present disclosure.

FIG. 1 is a flowchart illustrating a part of a method according to oneembodiment of the present disclosure.

FIG. 2 is a diagram illustrating an example of a configuration of aprocessing apparatus in which the method illustrated in FIG. 1 isexecuted.

FIG. 3 is a diagram illustrating an example of an execution state of aprocess illustrated in FIG. 1.

FIG. 4 is a flowchart more specifically illustrating the flowchartillustrated in FIG. 1.

FIG. 5 is a diagram more specifically illustrating an execution state ofthe process illustrated in FIG. 3.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. In the followingdetailed description, numerous specific details are set forth in orderto provide a thorough understanding of the present disclosure. However,it will be apparent to one of ordinary skill in the art that the presentdisclosure may be practiced without these specific details. In otherinstances, well-known methods, procedures, systems, and components havenot been described in detail so as not to unnecessarily obscure aspectsof the various embodiments.

Various embodiments will now be described in detail with reference tothe drawings. Further, like or equivalent parts in the respectivedrawings are given like reference numerals. FIG. 1 is a flowchart of aprocess A illustrating a part of a method MT according to one embodimentof the present disclosure. The method MT illustrated in FIG. 1 is amethod of processing a target substrate (hereinafter, referred to as a“wafer W”). The process A included in the method MT according to oneembodiment may be executed using a processing apparatus 1 illustrated inFIG. 2. FIG. 2 is a diagram illustrating an example of a configurationof the processing apparatus 1 in which the method illustrated in FIG. 1is executed.

The processing apparatus 1 includes carrier mounting ports 11, anatmospheric transfer chamber 12, a load lock module LLM1, a load lockmodule LLM2, a vacuum transfer chamber 13, a processing module PM1, aprocessing module PM2, a processing module PM3, and a processing modulePM4. The atmospheric transfer chamber 12, the load lock module LLM1, theload lock module LLM2, the vacuum transfer chamber 13, the processingmodule PM1, the processing module PM2, the processing module PM3, andthe processing module PM4 (the processing modules PM1 to PM4) aresequentially arranged in a loading direction of the wafer W, and areconnected to each other while maintaining airtightness via a door G1, adoor valve G2, a gate valve G3, and a gate valve G4.

A transfer container C is loaded on each of the carrier mounting ports11. The carrier mounting port 11 corresponds to a loading port of thetransfer container C. The transfer container C accommodates a pluralityof wafers W. The transfer container C is connected to the atmospherictransfer chamber 12 via the door G1.

The atmospheric transfer chamber 12 transfers the wafers W dischargedfrom the transfer container C under an air atmosphere. A transfer arm121 is installed in the atmospheric transfer chamber 12. The transferarm 121 can freely rotate, extend and contract, move up and down, andmove left and right. The transfer arm 121 takes out the wafers W one byone from the transfer container C and transfers the taken-out wafers W.An alignment chamber 14 is installed on the side surface of theatmospheric transfer chamber 12. The alignment chamber 14 incorporatesan orienter for aligning the wafers W.

Each of the load lock module LLM1 and the load lock module LLM2 isconnected to the atmospheric transfer chamber 12 via the door valve G2.In both of the load lock module LLM1 and the load lock module LLM2,their respective internal states are switched between an air atmosphereand a preliminary vacuum atmosphere to allow the wafers W to be in astandby state. Both the load lock module LLM1 and the load lock moduleLLM2 are disposed so as to connect between the atmospheric transferchamber 12 and the vacuum transfer chamber 13. A vacuum pump and a leakvalve (not shown) for switching the interior of each of the load lockmodule LLM1 and the load lock module LLM2 between the air atmosphere andthe vacuum atmosphere are connected to each of the load lock module LLM1and the load lock module LLM2. A mounting table 16 is installed in eachof the load lock module LLM1 and the load lock module LLM2. The mountingtable 16 mounts the carried-in wafers W thereon.

The vacuum transfer chamber 13 is connected to each of the load lockmodule LLM1 and the load lock module LLM2 via the gate valve G3. Thevacuum transfer chamber 13 transfers the wafers W under a vacuumatmosphere. The processing modules PM1 to PM4 are connected to thevacuum transfer chamber 13 via gate valves G4. The vacuum pump (notshown) for maintaining the interior of the vacuum transfer chamber 13 ina vacuum atmosphere is connected to the vacuum transfer chamber 13.

A transfer arm 131 is installed in the vacuum transfer chamber 13. Thetransfer arm 131 can freely rotate and extend and contract. The transferarm 131 transfers the wafers W between the load lock module LLM1, theload lock module LLM2, and the processing modules PM1 to PM4.

The processing modules PM1 to PM4 all execute a process on the wafers W.Each of the processing modules PM1 to PM4 has a process container PSwhich accommodates the wafers W, in which the process is performed onthe wafers W accommodated in the process container PS.

Each of the processing modules PM1 to PM4 can execute, for example, adifferent type of process, on the wafers W. In one embodiment, forexample, the processing module PM1 and the processing module PM2 may befilm forming modules for forming a thin film on the surfaces of thewafers W arranged in the process containers PS. In one embodiment, forexample, the processing module PM3 and the processing module PM4 may beplasma processing modules for generating plasma in the processcontainers PS and performing plasma processing on a thin film on thesurfaces of the wafers W arranged in the process containers PS.

The processing apparatus 1 further includes a controller 2. Thecontroller 2 comprehensively controls an operation of each part (thetransfer arm 121 or the like illustrated in FIG. 1) of the processingapparatus 1. The controller 2 may be configured as a computer deviceincluding a processor 2 a, a memory 2 b, a storage 2 c, a communicationdevice 2 d, an input device 2 e, an output device 2 f, a bus 2 g, andthe like. The processor 2 a, the memory 2 b, the storage 2 c, thecommunication device 2 d, the input device 2 e, the output device 2 f,and the like are mutually connected via the bus 2 g.

The operation of each part of the processing apparatus 1 is realized byreading a computer program (for example, a program for executing aprocess A) stored in the storage 2 c or the like or a computer programdownloaded from an external device via the communication device 2 d intothe processor 2 a and the memory 2 b and causing the processor 2 a toexecute the computer program. The processor 2 a may include a centralprocessing unit (CPU), a memory, and the like.

The memory 2 b is a computer-readable recording medium. The memory 2 bmay be configured to include at least one of, for example, a read onlymemory (ROM), an erasable programmable ROM (EPROM), an electricallyerasable programmable ROM (EEPROM), a random access memory (RAM), andthe like.

The storage 2 c is a computer-readable recording medium. The storage 2 ccan be accessed by the processor 2 a. The storage 2 c may be configuredto include at least one of, for example, an optical disc, a hard diskdrive, and the like.

The communication device 2 d is a transceiver device for performingcommunication between computers via a wired and/or wireless network. Thecommunication device 2 d is, for example, a network device, a networkcontroller, a network card, a communication module, or the like.

The input device 2 e is an input device (for example, a keyboard, amouse, a microphone, a switch, a button, a sensor, or the like) thataccepts an input from the outside. The output device 2 f is an outputdevice (for example, a display, a speaker, an LED lamp, or the like) forperforming outputting to the outside. The input device 2 e and theoutput device 2 f may be integrally configured (for example, a touchpanel).

An operation of processing the wafers W by the processing apparatus 1described above will be schematically described. The wafers Waccommodated in the transfer container C on the carrier mounting port 11are discharged by the transfer arm 121 and positioned in the alignmentchamber 14 during the transfer through the atmospheric transfer chamber12, and then transferred to one of the load lock modules LLM1 and theload lock modules LLM2.

After the wafers W are transferred to one of the load lock module LLM1and the load lock module LLM2, when the interior of each of the loadlock module LLM1 and the load lock module LLM2 becomes a preliminaryvacuum atmosphere, the wafers W are discharged by the transfer arm 131and transferred into the vacuum transfer chamber 13. Thereafter, thewafers W are transferred between the vacuum transfer chamber 13 and theprocessing modules PM1 to PM4, and processed in the processing modulesPM1 to PM4. The processed wafers W are accommodated in the transfercontainer C through a reverse path (excluding the alignment chamber 14)of the loading path.

Next, the method MT according to one embodiment of the presentdisclosure will be described. The method MT is a method of processing aplurality of wafers W. The method MT is executed under the control ofthe controller 2. The method MT includes a process A. The process Aserially executes multiple processes including a main process and firstto M-th subprocesses (where M is a positive integer in the presentdisclosure) in the process container PS. The content of the main processand the content of each of the first to M-th subprocesses are set inadvance in the controller 2 via the input device 2 e. The executiontimes of the first to M-th subprocesses may be different from eachother. The processes being serially executed means that multipleprocesses are executed sequentially (serially), more specifically, thatthe execution of a next process starts at the time when the execution ofone process is ended.

In one embodiment, for example, the main process processes a singlewafer W. The main process is executed serially multiple times in theprocess A. The main process is, for example, a process performed on thewafers W arranged in the process container PS by supplying a gas intothe process container PS, and may be a film forming process, an etchingprocess, or the like.

An i-th subprocess (where i is a positive integer that satisfies 1≤i≤Min the present disclosure) is executed once or multiple times in theprocess A. The i-th subprocess is executed subsequent to one or multipleconsecutive executions (corresponding to the i-th unit lot) of the mainprocess in the process A. In the process A, interruption of the first toM-th subprocesses occurs in the process where the main processes aresequentially executed. In other words, in the process where the mainprocess is sequentially executed, the main process is executedimmediately before the execution of the i-th subprocess, and the mainprocess is also executed immediately after the execution of the i-thsubprocess. The i-th subprocess may be, for example, a process ofpurging the interior of the process container PS.

In the process A, an index value N1 indicating one execution of the mainprocess is accumulated for each execution of the main process. Acumulative value of the index value N1 accumulated from the start of theprocess A is set as a cumulative value α. The cumulative value α at thestart of the process A satisfies α=0.

The index value N1 may be one of the number of wafers W processed by oneexecution of the main process or a thickness of a film formed on thewafers W by one execution of the main process when the main process is afilm forming process, the number of cycles and a plasma generating time,or a combination thereof. When the number of wafers W processed by oneexecution of the main process is 1, N1=1 [sheet]. When the thickness ofa film formed on the wafers W by one execution of the main process is,for example, 10 nm, N1=10 [nm]. Other units such as Angstrom may also beused as the unit of film thickness. The index value N1 is set in advancein the controller 2 via the input device 2 e before the execution of themethod MT.

A reference value N2 is a value for determining the completion (End) ofthe process A based on the cumulative value α, and is set in advance inthe controller 2 via the input device 2 e before the execution of themethod MT. The reference value N2 is a total number (upper limit value)of the number of wafers W processed in the process A when the indexvalue N1 is the number of wafers W processed by one execution of themain process. In the case where the index value N1 is the thickness of afilm formed on the wafers W by one execution of the main process whenthe main process is the film forming process, the reference value N2 isa total thickness number (upper limit value) of a film formed on thewafers W in the process A.

For the application of the i-th subprocess in the process A, the i-thsubprocess is applied to the process A when the cumulative value αsatisfies an i-th application condition. For the execution of the i-thsubprocess, the i-th subprocess is executed at the time when a totalvalue of the index value N1 obtained by one or multiple consecutiveexecutions of the main process (corresponding to the i-th unit lot)satisfies an i-th execution condition when the cumulative value αsatisfies the i-th application condition.

When i=k (where k is a positive integer that satisfies 1≤k≤M−1 in thepresent disclosure), a k-th application condition is that the cumulativevalue α satisfies L(k−1)<α≤L(k). L(k−1) and L(k) are values for definingthe range of the cumulative value α as the k-th application condition,and are real numbers of 0 or more. L(0)=0 and L(k−1)<L(k) are eachsatisfied. For example, when the cumulative value α indicates acumulative value of the number of wafers W, L(k−1) and L(k) are values[sheets] indicating the number of wafers W, and when the cumulativevalue a indicates a cumulative value of film thickness, they are values[nm] indicating a film thickness. When i=M, an M-th applicationcondition is an application condition of the M-th subprocess that islast applied in the process A among the first to M-th subprocesses, andsatisfies L(M−1)<α.

The i-th execution condition is that a total value β of the index valueN1 accumulated from the execution of a subprocess last executed whenthere is a subprocess already executed from the start of the process A,or a total value β of the index value N1 accumulated from the start ofthe process A when there is no subprocess already executed from thestart of the process A satisfies β>K(i). Here, K(i) is a positive realnumber, and defines an execution period of the i-th subprocess.

Both the content of the i-th application condition and the content ofthe i-th execution condition are set in advance in the controller 2 viathe input device 2 e before the execution of the method MT. The contentof the i-th application condition and the content of the i-th executioncondition are all changeable. More specifically, both L(i) and K(i) areset in advance in the controller 2 via the input device 2 e before theexecution of the method MT. In particular, L(M)=0 is set for L(M) whichis included in the M-th application condition of the M-th subprocessthat is last applied in the process A among the first to M-thsubprocesses. In other words, i when L(i)=0 is set to i=M. The contentsof L(i) and K(i) are all changeable.

The process A will be described in detail with reference to FIGS. 1 and3. FIG. 1 is a flowchart illustrating a part (process A) of the methodMT according to one embodiment of the present disclosure. FIG. 3 is adiagram illustrating an example of an execution state of the process Aillustrated in FIG. 1. The horizontal axis in FIG. 3 indicates acumulative value α of the index value N1 from the start of the process Ato the completion (End) of the process A. As illustrated in FIG. 1, theprocess A includes steps ST1 to ST10. In step ST1, when the process Astarts, initial values of three variables (α, β, i) used for theexecution of the process A are set. That is, they are set as: α=0, β=0,and i=1.

The index value N1 is added to both of the cumulative value α (α+N1→α)and the total value β (β+N1→β) in one of step ST2 subsequent to stepST1, step ST2 subsequent to step ST8 (“YES”) and step ST2 subsequent tostep ST10. In step ST3 subsequent to step ST2, the main process isexecuted. The main process is executed once in step ST3 and the indexvalue N1 indicating this one execution of the main process is added tothe cumulative value α and the total value β in step ST2. In thismanner, in the process A, α and β each increases by N1 each time themain process is executed once.

In step ST4 subsequent to step ST3, it is determined whether or not thei-th subprocess currently being applied is a subprocess which is lastapplied in the process A. More specifically, in step ST 4, it isdetermined whether L(i)=0 (i=M) is satisfied. In step ST5 subsequent tostep ST4 (“NO”), it is determined whether or not to continuously applythe currently applied i-th subprocess. More specifically, in step ST5,it is determined whether or not L(i−1)<α≤L(i) (L(0)=0, i<M) issatisfied. That is, in step ST4 and step ST5, it is determined which ofthe first to M-th subprocesses is being applied to the process A.

When L(i)=0 is satisfied in step ST4 (step ST4: “YES”), it is determinedthat at this point i=M and the M-th subprocess is applied to the processA. In step ST6 subsequent to step ST4 (“YES”), it is determined whetheror not to continue the process A. More specifically, in step ST6, it isdetermined whether or not α≤N2 is satisfied. When it is determined instep ST6 that α≤N2 is not satisfied (step ST6: “NO”), the process A isended, and when it is determined in step ST6 that α≤N2 is satisfied(step ST6: “YES”), the process after step ST8 is performed withoutending the process A.

In the case of step ST6 (“NO”), after the end of the process A, aprocess different from the i-th subprocess used in the process A may beexecuted, and then the process A may be repeatedly performed again.

In step ST4, when L(i)=0 is not satisfied (step ST4: “NO”), i<M is set.When L(i−1)<α≤L (i) (L(0)=0, i<M) is satisfied (step ST5: “YES”) in stepST5 subsequent to step ST4 (“NO”), it is determined that at this pointthe i-th subprocess is applied to the process A.

In step ST5, when L(i−1)<α≤L(i) (L(0)=0, i<M) is not satisfied (stepST5: “NO”), at this point, the i-th subprocess is not applied to theprocess A, and thus, in step ST7 subsequent to step ST5 (“NO”), an i+1subprocess subsequent to the i-th subprocess is applied to the processA. When step ST7 is executed, the value of i is incremented (increasedby 1) (i+1→i), and step ST4 is executed again.

An interval TR(i) illustrated in FIG. 3 is an interval at which the i-thsubprocess is applied to the process A, and an interval TR(i+1)illustrated in FIG. 3 is an interval at which the i+1 subprocess isapplied to the process A. The transition from the interval TR(i) to theinterval TR(i+1) illustrated in FIG. 3 is realized by incrementing iexecuted in step ST7. An interval TR(1), an interval TR(2), an intervalTR(M−1), and an interval TR(M) illustrated in FIG. 3 are similar to thecase of the intervals TR(i) and TR(i+1).

In step ST8 subsequent to step ST5 (“YES”), it is determined whether ornot the execution timing of the currently applied i-th subprocess isreached. More specifically, in step ST8, it is determined whether or notthe total value β satisfies β≤K(i). Here, K(i) defines the executionperiod of the i-th subprocess. Therefore, in step ST8, it is determinedwhether or not the i-th subprocess is executed.

When β≤K(i) is satisfied (step ST8: “YES”), it is determined that thei-th subprocess is not executed (the execution period of the i-thsubprocess is not reached). In the case of step ST8 (“YES”), the processproceeds to step ST2 and step ST3 where the main process is furtherexecuted. When β≤K(i) is not satisfied (step ST8: “NO”), it isdetermined that the execution timing of the currently applied i-thsubprocess has been reached. That is, in step ST8 (“NO”), it isdetermined that the i-th subprocess is executed. In the case of step ST8(“NO”), the process proceeds to step ST9 where the i-th subprocess isexecuted.

A timing SP(i) illustrated in FIG. 3 corresponds to the case where it isdetermined in step ST8 that β≤K(i) is not satisfied, and corresponds tothe execution timing of the i-th subprocess. A timing SP(1), a timingSP(2), a timing SP(i+1), a timing SP(M−1) and a timing SP(M) illustratedin FIG. 3 are similar to the case of the timing SP(i).

Since the i-th subprocess has been executed in step ST9, the total valueβ is reset to a value of zero (0→β) in step ST10 subsequent to step ST9.In a state in which the total value β is reset to zero, each processafter step ST2 is repeated, and it is determined again in step ST8whether or not β>K(i) is satisfied (it is determined whether or not thei-th execution condition is satisfied).

EXAMPLES

An example of the process A will be described with reference to FIGS. 4and 5. FIG. 4 and FIG. 5 may be diagrams illustrating the same example.FIG. 4 is a flowchart more specifically illustrating the flowchartillustrated in FIG. 1. The process A illustrated in FIG. 4 includessteps ST1 a to ST7 a. FIG. 5 is a diagram more specifically illustratingan execution state of the process A illustrated in FIG. 3. FIG. 5illustrates an execution state of the process A corresponding to theflowchart illustrated in FIG. 4.

When the execution of the process A illustrated in FIG. 4 starts, stepST1 illustrated in FIG. 1 is executed, and thereafter, step ST1 a isexecuted. Step ST1 a corresponds to step ST2 and step ST3 illustrated inFIG. 1, and step ST2 a corresponds to step ST4 illustrated in FIG. 1.Step ST3 a corresponds to step ST5 illustrated in FIG. 1, step ST4 acorresponds to step ST6 illustrated in FIG. 1, and step ST5 acorresponds to step ST7 illustrated in FIG. 1. Step ST6 a corresponds tostep ST8 illustrated in FIG. 1, and step ST7 a corresponds to step ST9and step ST10 illustrated in FIG. 1.

In one example illustrated in FIGS. 4 and 5, the main process is a waferprocess for processing a wafer W using a gas (further using plasma),such as, for example, a film forming process or an etching process, andthe i-th subprocess is a purge process for purging the interior of theprocess container PS in which the wafer processing process has beenperformed. In one example illustrated in FIGS. 4 and 5, the process Acan be performed after the process of cleaning the interior of theprocess container PS using, for example, a ClF₃ gas.

In one example illustrated in FIGS. 4 and 5, the index value N1 is athickness [nm] of a film formed on the wafer W by one wafer process(main process). Therefore, both the cumulative value α and the totalvalue β correspond to a cumulative value [nm] of film thickness. SinceL(i) used for the i-th application condition (see step ST5 illustratedin FIG. 1) is also a value for defining the range of the cumulativevalue α, similar to the cumulative value α, it corresponds to a value[nm] of the film thickness. Since K(i) used for the i-th executioncondition (see step ST8 illustrated in FIG. 1) is also a value fordefining the range of the total value β, similar to the total value β,it corresponds to a value [nm] of the film thickness. For example, asillustrated in FIG. 5, there may be L(1)=3,000 [nm], K(1)=700 [nm], andK(2)=500 [nm].

In the process A illustrated in FIG. 4, the wafer process correspondingto the main process is executed in step ST1 a. In step ST2 a subsequentto step ST1 a, it is determined whether or not the purge processcorresponding to the currently applied i-th subprocess is a purgeprocess corresponding to the M-th subprocess which is last applied inthe process A.

When it is determined in step ST2 a that the currently applied purgeprocess (the i-th subprocess) is not the purge process corresponding tothe M-th subprocess which is last applied in the process A (step ST2 a:“NO”), the process proceeds to step ST3 a where it is determined whetheror not to continuously apply the purge process corresponding to thecurrently applied i-th subprocess. In order to determine whether or notto continuously apply the purge process corresponding to the currentlyapplied i-th subprocess in step ST3 a, when i=k (where k is a positivenumber that satisfies 1≤k≤M−1), a k-th application conditionL(k−1)<α≤L(k)) is used (see step ST5 illustrated in FIG. 1).

When it is determined in step ST3 a to continuously apply the purgeprocess corresponding to the currently applied i-th subprocess (step ST3a: “YES”), the process proceeds to step ST6 a. When it is determined instep ST3 a not to continuously apply the purge process corresponding tothe currently applied i-th subprocess (step ST3 a: “NO”), the processproceeds to step ST5 a where the purge process is changed from the purgeprocess corresponding to the currently applied i-th subprocess to apurge process corresponding to an (i+1)th subprocess to be applied next,subsequent to the purge process corresponding to the currently appliedi-th subprocess, and after this change, the process returns to step ST2a.

When it is determined that the purge process corresponding to thecurrently applied i-th subprocess is the purge process corresponding tothe M-th subprocess which is last applied in the process A (step ST2 a:“YES”), the process proceeds to ST4 a where it is determined whether ornot to continue the process A. That is, in step ST4 a, it is determinedwhether or not the cumulative value α exceeds the reference value N2that is the upper limit value of the number of wafers W processed instep ST4 a (see step ST 6 illustrated in FIG. 1). In step ST4 a, when itis determined not to continue the process A (the cumulative value α hasexceeded the reference value N2) (step ST4 a: “NO”), the process A isended. In step ST4 a, when it is determined to continue the process A(the cumulative value α has not exceeded the reference value N2) (stepST4 a: “YES”), the process proceeds to step ST6 a.

Further, in the case of step ST4 a (“NO”), after the process A is ended,a process (for example, dry cleaning) different from the purge processcorresponding to the i-th subprocess used in the process A is executed,and thereafter, the process A may be repeatedly executed.

In step ST6 a, it is determined whether or not the current timing hasreached the execution timing (SP(i)) of the purge process correspondingto the i-th subprocess. In step ST6 a, β≤K(i) is used in order todetermine whether or not the current timing has reached the executiontiming (SP(i)) of the purge process corresponding to the i-th subprocess(see step ST8 illustrated in FIG. 1). When it is determined that thecurrent timing has not reached the execution timing (SP(i)) of the purgeprocess corresponding to the i-th subprocess (step ST6 a: “NO”), theprocess proceeds to step ST1 a which executes the wafer process, and theprocesses after step ST1 a are repeated.

When it is determined that the current timing has reached the executiontiming (SP(i)) of the purge process corresponding to the i-th subprocess(step ST6 a: “YES”), the process proceeds to step ST7 a which executesthe purge process corresponding to the currently applied i-thsubprocess. After step ST7 a, the process proceeds to step ST1 a whichexecutes the wafer process to repeat the process after step ST1 a.

For example, as illustrated in FIG. 5, when the cumulative value α ofthe film thickness accumulated from the start of the process A exceedsL(1) (=3,000 [nm]) which does not satisfy a first application condition(step ST3 a: “NO”), in step ST5 a, the purge process is changed from thepurge process corresponding to a first subprocess currently beingapplied to a purge process corresponding to a second subprocess to beapplied next. In this case, after step ST5 a, since the currentlyapplied purge process becomes the purge process corresponding to thesecond subprocess, K(1) (=700 [nm]) used for determining the executiontiming of the purge process in step ST6 a is also changed to K(2) (=500[nm]), and K(2) is used in this determination of step ST6 a (step ST8illustrated in FIG. 1).

Therefore, the timing SP(2), in which the purge process corresponding tothe second subprocess is first executed after the cumulative value αexceeds L(1), is a timing (the timing when the cumulative value α firstexceeds 2,800+K(2)=3,300 [nm]) that the total value β from the timingSP(1) (the timing when the cumulative value α first exceeds 5×K(1)=2,800[nm]), in which the purge process corresponding to the first subprocessis last executed while the cumulative value α is less than or equal toL(1), first exceeds K(2).

Accordingly, when a cleaning of the process container PS has alreadybeen completed at the start of the process A, the execution of theprocess A progresses such that the frequency and execution time of thepurge process for purging the interior of the process container PS aresuppressed for a while after the start of the process A. As the effectof cleaning before the start of the process A decreases, the frequencyand execution time of the purge process are increased. Thus, it ispossible to sufficiently reduce generation of particles over theexecution period of the process A.

As described above, since the generation of particles is relativelysmall in the initial stage of the process A in which the effect ofcleaning before the start of the process A is sufficiently maintained,it is possible to reduce a downtime caused by conditioning bysuppressing the frequency and execution time of the purge process.

In a situation where the generation of particles can gradually increaseas the execution of the process A progresses and the cumulative value αincreases, by gradually increasing the number of executions of the purgeprocess corresponding to the i-th subprocess while gradually shorteningthe execution period of the purge process corresponding to K(i), namelythe i-th subprocess, it is possible to strongly execute the purgeprocess within a short period at the end of the process A where thegeneration of particles tends to increase. As a result, it is possibleto sufficiently prolong the execution period of cleaning for the processcontainer PS executed before and after the process A.

According to the aforementioned method MT, since the condition forinvolving the i-th subprocess in the process A in which multiple mainprocesses are serially executed, namely both the i-th applicationcondition for the i-th subprocess to be applied to the process A and thei-th execution condition for the i-th subprocess to be executed in theprocess A, can be set to be changeable, when multiple processes areserially executed in the process A, the execution aspect of each processsuch as the order of executing the process, the timing of executing theprocess, or the like can be flexibly set.

Furthermore, since the k-th application condition for applying the k-thsubprocess when i=k is L(k−1)<α≤L(k) and the M-th application conditionfor applying the M-th subprocess when i=M is L(M−1)<α, the i-thsubprocess can be sequentially applied in the process A as thecumulative value α increases (the increase in the number of wafers Wprocessed by the main process). In addition, the change of the i-thapplication condition can be realized by changing L(i).

Moreover, since the i-th execution condition for executing the i-thsubprocess is β>K(i), where β is the total value β of the index valueaccumulated from the execution of a subprocess last executed when thereis a subprocess already executed from the start of the process A or thetotal value β of the index value accumulated from the start of theprocess A when there is no subprocess already executed from the start ofthe process A, β increases according to the increase in the number ofwafers W processed by the main process, and the i-th subprocess can beexecuted at the time when β exceeds K(i). In addition, the change of thei-th execution condition can be realized by changing K(i).

Furthermore, the i-th application condition for the i-th subprocess tobe applied in the process A and the i-th execution condition for thei-th subprocess to be executed in the process A may be appropriately setbased on either the number of wafers W processed by one execution of themain process or the thickness of a film formed on the wafers W processedby one execution of the main process when the main process is a filmforming process.

In addition, the main process can be a process which is performed on thewafers W arranged in the process container PS by supplying a gas intothe process container PS, and the subprocess can be a process of purgingthe interior of the process container PS. In this case, since theexecution timing of the subprocess can be adjusted in the process A inwhich the main processes are serially executed, the improvement of theeffect and reduction of the load due to the purge can be appropriatelyrealized, considering the content of the main process and the content ofcleaning that can be executed before and after the process A. Forexample, in the case where the process A is started using the processcontainer PS after it is cleaned, since the timing immediately after thestart of the process A is the timing immediately after the processcontainer PS is cleaned, it is possible to make the execution period ofthe purge (the execution period of the subprocess) relatively longer andto make one purge time (the execution time of the subprocess) relativelyshorter. In addition, as the process A approaches to the end, sincedeposits or the like may increase in the process container PS accordingto multiple executions of the main process, it is possible to make theexecution period of the purge (the execution period of the subprocess)relatively shorter and to make one purge time (the execution time of thesubprocess) relatively longer.

According to the present disclosure in some embodiments, it is possibleto provide a technique capable of flexibly setting an execution aspectof each process such as the order of executing the process, the timingof executing the process or the like when multiple processes areserially executed.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the embodiments described herein maybe embodied in a variety of other forms. Furthermore, various omissions,substitutions and changes in the form of the embodiments describedherein may be made without departing from the spirit of the disclosures.The accompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of thedisclosures.

What is claimed is:
 1. A method of processing a target substrate,comprising: a process of serially executing multiple processes includinga main process and first to M-th subprocesses (where M is a positiveinteger), wherein an index value indicating one execution of the mainprocess is accumulated for each execution of the main process, the mainprocess is executed multiple times in the process of serially executingmultiple processes, an i-th subprocess (where i is a positive integerthat satisfies 1≤i≤M) is executed once or multiple times in the processof serially executing multiple processes, the i-th subprocess isexecuted subsequent to one or multiple consecutive executions of themain process, the i-th subprocess is applied to the process of seriallyexecuting multiple processes when a cumulative value of the index valueaccumulated from a start of the process of serially executing multipleprocesses satisfies an i-th application condition, when the cumulativevalue of the index value accumulated from the start of the process ofserially executing multiple processes satisfies the i-th applicationcondition, the i-th subprocess is executed at a time when a cumulativevalue of the index value accumulated from execution of a last executedsubprocess when there is a subprocess already executed from the start ofthe process of serially executing multiple processes or a cumulativevalue of the index value accumulated from the start of the process ofserially executing multiple processes when there is no subprocessalready executed from the start of the process of serially executingmultiple processes satisfies an i-th execution condition, and both thei-th application condition and the i-th execution condition arechangeable.
 2. The method of claim 1, wherein a is the cumulative valueof the index value accumulated from the start of the process of seriallyexecuting multiple processes and a k-th application condition (where kis a positive integer that satisfies 1≤k≤M−1) is that the cumulativevalue α satisfies L(k−1)<α≤L(k), L(k−1) and L(k) are real numbers of 0or more and satisfy L(k−1)<L(k), and an M-th application condition ofthe M-th subprocess that is last applied in the process of seriallyexecuting multiple processes among the first to M-th subprocesses isthat the cumulative value α satisfies L(M−1)<α.
 3. The method of claim1, wherein the i-th execution condition is that a total value β of theindex value accumulated from the execution of the last executedsubprocess when there is a subprocess already executed from the start ofthe process of serially executing multiple processes, or a total value βof the index value accumulated from the start of the process of seriallyexecuting multiple processes when there is no subprocess alreadyexecuted from the start of the process of serially executing multipleprocesses satisfies β>K(i), and K(i) is a positive real number.
 4. Themethod of claim 1, wherein the index value is either the number oftarget substrates processed by one execution of the main process or athickness of a film formed on the target substrates by one execution ofthe main process when the main process is a film forming process.
 5. Themethod of claim 1, wherein the main process is a process performed onthe target substrate arranged in a process container by supplying a gasinto the process container, and each of the subprocesses is a process ofpurging an interior of the process container.